phr. The teacher is the only person who can answer this question.
phr. Only with time it is possible to understand how valuable love is
phr. Only if one studies modestly can they go forward.
phr. Only by developing a favorable/favourable plan can the production efficiency be improved.
phr. It seems that only my presence can solve this problem.
phr. Only your teacher can answer your questions.
phr. Only if you study hard, can you get good result in the exam.